Tubing cutters have been run into a subterranean location into tubing that is to be cut on coiled tubing and/or tubular. The coiled tubing or tubular has fluid pumped through it to power a downhole motor that is fluid driven such as a progressing cavity pump. The rotation of the pump drives the cutter after extending its blades. Some examples are U.S. Pat. Nos. 7,225,873 and 7,086,467. Coiled tubing units are frequently not at a well site and are very expensive to deploy.
Older designs would cut tubing using explosive charges that are set off with a dropped weight on a slickline such as illustrated in U.S. Pat. No. 5,992,289. These tools did not rotate and the positioning of the explosives made the circumferential cut. These designs had the obvious safety issues of dealing with explosives. The extension reach of the explosion could damage the outer string on the back side of the tubing being cut.
Rotating tubing cutters have been run in on wireline where power was transmitted to an electric motor in the bottom hole assembly as illustrated in U.S. Pat. No. 7,370,703.
Other assemblies disclose the use of a tubing cutter but the focus is on how the blades are extended or how the cutter is anchored with no details about the drive system other than stating that there is a driver and that the traditional conveyances for cutters such as coiled tubing, wireline or slickline can be used. Some examples are U.S. Pat. Nos. 7,478,982 and 7,575,056.
Slickline has been used in conjunction with an anchor and tubular cutter that is rotated by a motor having a battery as the power supply as shown in U.S. Pat. No. 8,210,251. Tractors have been used with local power supply in the form of a battery to advance a BHA to the desired location in a deviated wellbore while at the same time avoiding slack or over-tensioning the slickline used to deliver the BHA as is described in U.S. Pat. No. 8,151,902.
There are many occasions where a coiled tubing unit or an E-line rig is not available and a need to cut tubing or mill arises. Under those circumstances it would be advantageous to use a slickline supported cutter. Since a slickline cannot convey power and a self contained power supply in the bottom hole assembly, such as a battery, may not have the output to get the job done or may not even fit in a confined location of a small wellbore, the present invention provides an alternative to make the tubing cut or to advance a mill as a fish is being milled. A fish is the stuck object in the wellbore. A washover mill goes around the exterior of the fish such as a packer to undermine the slips so that the packer can be released and in general fall further down in the hole or actually get fished out. A washover mill can be fitted with a tool to grasp the released fish for retrieval. A slickline or wireline cannot push a mill forward as the milling progresses and thus the present invention contemplates ways to deploy a fluid motor run on electric line or slick line to advance the mill or to put a force on the mill against the fish during milling. More specifically telescoping joints that are spring loaded with fluid pressure are contemplated as well as a tractor in conjunction with a telescoping joint with the tractor powered by wireline or a local power source such as an onboard battery.
The preferred deployments of the invention is in a well with production tubing inside casing where the tubing is cut to be freed from a production packer by allowing it to extend so that its slips and sealing system can retract or washover milling of a stuck fish. In the context of this application, the reference to “tubing” is to tubular strings in a wellbore and includes casing, production or injection tubing in casing or tubulars in other environments that need to be cut. In the preferred mode the rig pumps provide fluid under pressure around the bottom hole assembly that is supported in the tubular to be cut in a sealed manner and retained against reaction torque from the cutting or milling operation. The pumped fluid enters the bottom hole assembly through a ported sub and goes to a fluid driven pump such a progressing cavity pump to operate the cutter or mill. With a telescoping assembly to let a mill advance, the pressurized fluid can be used as a force to compress springs that are used to keep a force on the mill and against the fish as the milling progresses. Exhaust fluid from the pump goes out the tubing and back to the surface through perforated holes in the tubing allowing access to the annulus where the tubing inside the casing is being cut or a fish is being milled out. Those skilled in the art will more readily appreciate other aspects of the invention from a review of the detailed description and the associated drawings that appear below while recognizing that the full scope of the invention is to be found in the appended claims.